Was it Worth It? One Asian Carp Found After Six Miles of River Poisoned in Illinois

An emergency operation to stop invasive Asian carp from reaching the Great Lakes used more than 2,000 gallons of rotenone to poison six miles of a canal near Chicago this week. Tens of thousands of fish were killed. Just one Asian carp, the target of the poisoning, was found. An estimated 100 tons of dead fish will be taken to a landfill.

Why haven't more of the voracious, monster Asian carp been found? Studies have shown that Asian carp tend to sink to the bottom when they die. And even if more aren't found, killing all those other fish was worth it, some environmental groups say.

The fish kill will allow the U.S. Army Corps of Engineers to conduct maintenance on an electric fence built to keep the carp from sneaking into Lake Michigan.

"The last thing the National Wildlife Federation wants to see is dead fish, even in a sewer canal," said Andy Buchsbaum, Great Lakes Regional Executive Director for the group, billed as the nation's largest wildlife conservation organization.

"But in this case, the Illinois (Department of Natural Resources) showed strong leadership and commitment in doing a very difficult job. Without the agency's successful handling of this operation, the Great Lakes would be devastated by these monster carp."

Buchsbaum said finding even one Asian carp near the electric fence is cause for concern and "shows that we must now wage an all out war to keep these invaders out of the Great Lakes."

The lone Asian carp measured 22 inches. But as a species, the Asian carp has the potential to colonize the Great Lakes, experts say. Some of the swimmers grow to be 4 feet long and tip the scales at 100 pounds.

One possible measure: A biobullet, or specialized poison pill that could be made small enough to target Asian carp when they suck it up through their gills, according to the Detroit Free Press.